Fire Protection

Question 1

What happens when either illuminated Master FIRE WARN light is pushed?

Answer 1

Extinguishes both FIRE WARN lights, and

Silences the Fire Warning Bell, and

Resets the system for future warnings, and

Silences the remote APU fire warning horn (on the ground)

Question 2

What other switches provides the same function as pushing either Master FIRE WARN light for an engine fire warning?

Answer 2

Fire Warning BELL CUTOUT switch

Question 3

Which bus powers the engine overheat and fire detection? Which bus powers the engine fire extinguishing?

Answer 3

Engine overheat and fire detection - battery bus

Engine fire extinguishing - hot battery bus

Question 4

What will cause an illuminated ENG OVERHEAT light and/or engine fire switch to extinguish?

Answer 4

The temperature in the fire loop(s) drop below the onset temperature

Question 5

With the OVHT DET switch in the A or B position, what initiates an over or fire warning?

Answer 5

The selected loop

Question 6

With the OVHT DET switched selected to A during an overheat/fire test, what does an illuminated FAULT (amber) light mean?

Answer 6

Loop A has failed

Question 7

If one overheat/fire detector loop fails with the OVHT DET switch on NORMAL, how is a fire detected?

Answer 7

The remaining loop

Question 8

What does rotating an engine fire switch do?

Answer 8

Discharges the selected fire extinguishing squib into the associated engine

Question 9

What does pulling an engine fire switch up do?

Answer 9

Arms the fire extinguishing bottle
Closes the engine and spar fuel valves
Closes the engine bleed air valve
Closes the hydraulic fluid shutoff valve
Trips the generator control relay and breaker
Deactivates the associated engine thrust reverser

Question 10

What causes a fire switch to unlock?

Answer 10

Illumination of the associated fire switch, or

Manual unlock

Question 11

What power source is required for main wheel well fire detection?

Answer 11

2 AC Transfer Bus

Question 12

Which bus powers the APU overheat and fire detection? APU fire extinguishing?

Answer 12

APU Fire Detection - Battery Bus

APU Fire Extinguishing - Hot Battery Bus

Question 13

What does pressing the HORN CUTOUT switch on the APU fire control panel in the main wheel well do?

Answer 13

Silences the horn in the wheel well
Flashing light –> steady
Silences the fire warning bell in the flight deck

Question 14

What components are tested with the Overheat/Fire Protection Panel Test Switch to OVHT/FIRE?

Answer 14

Engine and APU Overheat
Engine, APU, and Wheel Well Fire
Associated flight deck indications (bell, master fire, master caution, and respective lights)

Question 15

What components are tested with the Overheat/Fire Protection Panel Test Switch to FAULT/INOP?

Answer 15

Fault detection circuits

Both Master Cautions
OVHT/DET system annunciator
FAULT light
APU DET INOP

Question 16

What does a FAULT light (amber) illuminating during an OVHT FIRE test indicate?

Answer 16

A failed engine loop

Question 17

What does the ENGINES APU EXT/TEST switch test?

Answer 17

Squib circuitry

Question 18

What does a DETECTOR FAULT light (amber) illuminated indicate when TEST is pushed and held on the cargo fire panel?

Answer 18

One or more detectors in a loop has failed

Question 19

What is the schedule for lower cargo fire bottle discharge?

Answer 19

First bottle - immediately

Second bottle - (if airborne) after 60 min it is metered for 135 min (195 min from initial activation)